Molecular Design And Preparation Of Several Organic Nonlinear Optical Materials

In this thesis, molecule designing and crystal engineering of the organic second-order nonlinear optical (NLO) material are studied in three chapters below:Chapter 1: Introduced briefly the theoretical and applied research of the nonlinear optical materials, their structural characteristics and the main methods in their molecule designing and crystal engineering.Chapter 2: 1,5-diphenylpenta-2,4-dien-1-ones as the second-order NLO materials were investigated, at both the molecular and the crystal level. Different substituents and substituent location could affect the nonlinearity greatly. The Important function of the bromo group in improving the properties of organic NLO materials was analyzed, and the way the conjugation length influence the micro- and macro-nonlinearity of the two series of compound, R2C6H4(CH=CH)nCOC6H4-R1(n=0, 1), was found theoretically and experimentally.Chapter 3: More facts were provided to support the conclusions drawn from chapter 2. Cinnamilidene anilines(CAs) as the second-order NLO materials were studied, at both the molecular and the crystal level. The substituent effects, especially the function of the bromo group in optimizing the properties of CAs NLO materials were discussed, and the way the conjugation length influence the micro-and macro- nonlinearity of the two series of compound, R2C6H4N=CH(CH=CH)nC6H4R1(n=0,1), was discovered, theoretically and experimentally.